Ｏｂｊｅｃｔｉｖｅ　To study the effect of the liberal fluid on vital signs of patients undergoing ileus surgery.　Methods　Sixty patients undergoing the ileus surgery with intravenous-inhalation anesthesia from January 2013 to September 2014， were randomly divided into two groups by the random number table method（n=30）： group N with normal fluid and group L with liberal fluid. Fluid volume： before anesthesia， group N was infused with sodium lactate ringer's solution 4 ml/kg and group L with sodium lactate ringer's solution 15 ml/kg. During the surgery， group N was infused with 15 ml·kg-1·h-1 and group L with 40 ml·kg-1·h-1 until the completion of suture of skin. Haemorrhage patients， depending on blood volume and hemoglobin level， were infused with hydroxyethyl separately， or with concentrated red blood cell suspension and fresh freezing plasma collectively. Heart rate（HR）， mean arterial pressure（MAP）， central venous pressure（CVP）， urine volume（UV） were monitored at the time points of entrance， ileus relieving and suture of abdominal.　Results　The per minute vital signs HR［（81±5） bpm vs （102±12） bpm］， MAP［（98±10） mmHg vs （77±8） mmHg（1 mmHg=0.133 kPa）］， CVP［（9.5±0.7） cmH2O vs （6.5±0.5） cmH2O（1 cmH2O=0.098 kPa）］（P<0.05） were obviously less fluctuated in group L than that in group N， wheras the urine volume ［（320±50） ml vs （90±20） ml ］（P<0.05） was more in group L than in group N. In addition， there were seven cases in group N used normal fluid requiring ephedrine in order to maintain blood pressure.　Conclusions　For ileus surgery patients， using liberal fluid may help keeping the vital signs stable， providing a sufficient blood perfusion in the key organs and tissues and ensuring patients safty during operation.